I (18M) am struggling with the idea of having a relationship with a guy (27M) with much more sexual experience.

Hey all, I've been dating a guy named Matt (fake name) I met on Tinder for nearly three months now. We've been having a blast together eating out, seeing movies, taking strolls through the park; the age gap used to be a big concern, but we've reached a point these days at which we can go entire dates without mentioning it. It didn't take long for us to be cuddling together in bed as if we're already a couple. What takes part in how smoothly it's been going is that I am simply unusually mature for my age (cliché, I know) – he's admitted that as well and it's the main reason why no one in my social circle bats an eye. Guess they expected it. Anyhow, after these months we're obviously sort of nearing the day on which we make it official (he more or less asked me yesterday) but something bugs me.

Before Matt, I'd never gone on a genuine date, kissed somebody on the lips, or had sex with somebody. He's my first in every romantic prospect. It's part of why I've enjoyed my time so much with him; he's very gentle and caring and has done nothing but his best to make those first experiences amazing for me. And they've been amazing! Thing is, Matt himself was far from a virgin. Two weeks ago he told me he's had a LOT of sex in the past, which he estimated to be even more on our second last date. But it's not the number that bothers me; it's the ratio of my sexual experience to his. If, say, he's had sex in a 100 different ways (person, situation, etc.), and if we were to enter a (monogamous, since neither of us are open to polygamy) relationship, I would indefinitely have to live with the knowledge that he quite literally has 100 times as much sexual experience as I, and that that'd indefinitely remain that way. And I can't tell whether I can live with that.

There's a lot that plays a significant role here. I was never much of a confident guy; he's boosted it by a lot, meaning I would be far more comfortable hooking up with others now than before if I wasn't exclusively dating somebody. I feel like I'm now entering a phase in which I could be entirely free to kiss, date & fuck whomever I want, except I'm not. On the other side of the coin, is an incredibly loving and beautiful bond between two people who share many interests and could probably make a fantastic couple in every possible way. In fact, I LOVE him, and he's told me he loved me. I have no doubts that I want to be his boyfriend officially, but I'm scared that the inferiority on a sexual level would sting me forever. And I can't figure out a solution. I would NEVER be able to forgive myself if I were to hook up with a bunch of guys now that we're not official partners yet (no matter whether I did or did not tell him); as I said, an open relationship is the last thing we want, and I don't know whether it's reasonable to keep our distances for a bit & allow me to experiment. Would that give me the satisfaction I don't have right now; would that build an awkward foundation under our relationship; would I risk losing him forever to somebody else? If I were to say, fuck it, I'm doing this with him, would I adjust to the idea? Is that the sort of obstacle I need to vanquish for the sake of love? Because maybe it is.

I know for certain that I am ready for a stable relationship. I've always dreamt of having that sort of a connection with somebody. The sole thing I feel I am missing is a lack of experience with casual sex, since every other experience isn't tied to love and will likely come with my years in university anyway. I'm going to address this to him as well the next time I see him; it's in the weekend, but it's too serious of a subject for over text. I've told myself for now to enjoy our time together while we're still dating and make the decision when that period ends; but there's now a lump in my throat when I talk to the man I used to be able to be entirely open to : ( does it genuinely come down to the "two people in completely different stages of life" cliché? Let me know if anyone's got any advice, I could really use some.

TL;DR: I want nothing more than a relationship with this guy, but he has had a complete sex life whereas I've only had sex with him, and I don't know if I could live with that.