Carpark chat goes further

I'm (M) friends with a woman quite a lot younger than me. She's 23, I'm knocking 50. She was my student until recently, and we've kept in touch since she graduated. We have a routine where we meet at a Country Park, have a walk, coffee etc. There is attraction, but we're both in relationships. Time before last, the peck on the cheek and hug became a long snog. Late time we met the weather had turned. We did the coffee and walk, but we were getting cold. Instead of a second coffee from the coffee cart and a seat by the lake, we took the coffees to the car. We chatted. Drank. Then the snog happened again, but this time her hand went down to my belt. Out came my hard cock. Stroking first. Slowly, then a full wank action, before she drops down and sucks my cock. Swallow my cum. We say goodbye and I we go back to our respective wife/husband respectively. Seeing her again next week. Starting to feel like an afair.