[Xtsxx]

Started work a few months ago and always really got along with him. We started to talk more and stay later after work just to chill together. Hes really funny, good looking and we just get along so well. Im 17, hes 26. So thats the first "problem" idm that too much tho. He always used nicknames to call me over which were flirty to begin with such as shorty but recently hes started to call me good looking by saying little things like "thanks gorgeous" or "only cos youre cute"!! I started to really really like him. Just the other week i found out he has a girlfriend tho. So obvs i think my feelings will just have to stay to myself. We still acted the same at work tho, it was all harmless.
Just the other day, we were by ourselves and he told me that he likes me and that he thinks i feel the same way. He then says "but im alot older than you and i have a girlfriend". So we went back inside and it was as if thats now cleared up that nothing can happen. There was loads of tension between especially when we stood close to eachother. I should have just gone home at that point but we ended up kissing. He texted me later as usual to see if i had gotten home safe. The next day when everybody else had finally left we were able to speak about it. He was understanding that if he has a girlfriend i dont want to do anything with him. But im weak and we ended up making out again. I was so hot and has made me only like him even more.
WHAT AM I DOING. Am i really in the wrong rn and should back away? Or idk just want to hear your thoughts. Its all i can think about.