AITAH for sleeping with my friends boyfriend?

I (33m) am married (32m) and we are open. My friend (32m) is in an open relationship with his boyfriend (27m).

My friends boyfriend and my husband are very similar people and so I find him attractive. My friend and his bf came to visit recently for a few days and while they were here I had sex with his boyfriend a couple times. Now, before they visited, I asked if my friend was ok if anything sexual happened between their bf and me while they were visiting and they said they didn't think anything would happen but their bf can make their own choices. I again clarified if they would have a problem and they said no.

After their visit they have been a bit grumpy with me and I feel like it is because of what happened with me and their bf. The way I see it is that I made sure to clarify before hand so consent was granted.

Am I the asshole?