I was out with a friend last night and we bumped into her friend and his wife. It was the end of the night and we realised that I live very close to my friends friends (married couple) so we shared a taxi, me him and his wife. He asked for my number in the taxi so I could let him know I got home safe (taxi dropped me after them) he asked for this in front of his wife. I text him when I got in to say home, let me know how much I owe you guys for the taxi. He replied to say thanks, it would be good to catch up soon and put a kiss (I never put kisses to men in relationships) he then text me today to ask how something had gone that I mentioned I was doing this morning when we were chatting last night with my friend the four of us. He is 20 years older than me. I'm aware I'm probably overly cautious as I'm a single woman and he's a married man but I don't know??