In love with my sisters brother - in - law

So i basically met my so called sisters brother in law (hes my sister bestfriends, whos like my sister, brotherinlaw) a couple Years back and we never really spoke. Then I met him again at the wedding and we go on like a house on were both in relationships. So nothing ever happened but we just Really Got on. Since then, we speak a lot and we've both become single near enough call everyday. But he has been going through a lot and only been speaking to me about it. We still havnt done anything beside cuddle in bed once and that was all thag ever happend. Hes alwaya been really flirty with me. And last night I was on the phone to. Someone new ive been talking to And my sister brother-in-law said to me theres this girl i like and She likes me, but she's always showing off that she can get other guys What should I do? Should I go for it or leave it. I said leave it but then realised that he might be talking about me so i said mayne shes just doing it to make you jealous. He then said hes texting her saying i need to gather my thoughts. Ive been in love with him since the day i met him but i have a date on friday because i never thought anything would happen with us. I dont know what to do. Should i just wait for him or do i continue with my life