I have to agree with everyone else and say that yes, was absolutely a pick up attempt! 😛 I also know how you feel about being so surprised they don't know that you're trans.. I always kind of assume that people know as I'm like 6'0" and have only been on HRT for 6 months, I get told that I pass but I kinda figure people are just trying to be nice..
Well I had a very similar thing happen to me last night which has changed my mind a little.
I'm Argentina for a wee surgical revision, I'm just about healed and will be going home tomorrow. I decided to go out and have a few drinks in the early evening (I get lonely as I'm on my own, and its just nice to be around people sometimes), well a couple of Argentinian guys sat down at the next table, and one was all smiles at me etc. he tried to talk but I only know about 5 words in spannish lol. It turns out his friend knows a little English, but not so good with the speaking, so we started talking via typing onto smartphone screen and passing it back and forth, which was kind of fun- especially as I was super lonely, so they found out that I'm from NZ and that I like Argentinian wine, yadda yadda.. It was all nice. The he started asking if I liked his friend etc., and he was quite good looking, so I said I kinda did lol.. it got to the point where I thought I'd better tell them I was trans though (there were lots of people around and I felt pretty safe but I was still freaked a bit..), well it turns out they had NO idea lol.. I was quite flattered 🙂