So back in November 2016 a buddy of mine and his girlfriend (let's call her Emily) broke up they'd drifted apart the breakup wasn't a suprise to many regardless of them having been together for quite some time. I've been friends with them both ever since school same classes group of friends so on so forth and I didn't really want to take a side the breakup seemed amicable no drama or anything. Fast forward about 6 months I'm in the middle East deployed with the military and I'm planning on going travelling in Europe when I get home I've been consistently asking friends to come along if they have a bit of time free but most are busy with work so on fair enough I'm happy to go alone anyway. I ended up texting my buddy's ex like I said we're friends anyway and I know she's travelling in Asia and casually mention that in going travelling in Europe mainly asking her for any advice on it and I just mention that if she's free she should come with me and to my suprise about a day later I get a message from saying she'll come along. I'm quite surprised happy and worried at the same time it'll be good to have some company but I'm worried I may have crossed some sort of line with my pal back home.

Anyway I get back home a few months later and tell my friend about what's happening reassure him that it's not my intention to hook up with her.

So we go travelling and to cut a long story short about 2 weeks in we end up sleeping together not out of any plan it just happens and have a really great time for the next 3 weeks or so with the intention to break it off when we get back. So she goes back I spend another 2 weeks travelling. Now I also felt really bad that we were doing this in secret no one knew anything was happening we kept it very hush hush and planned on keeping it that way until I told my buddy. So when I got home I went to his house and explained he seemed ok with it but it was definitely an awkward atmosphere so I left relatively quickly. I told my best friend soon after and word started to spread and that's when all the drama with friends started saying that it wasn't fair and I wasn't a good friend and it made both me and Emily feel horrible because it's not like it was a one night stand we actually really enjoyed each others company and wanted to make a go of it and be happy but everyone's opinions kind of ruined the mood. For those of you wondering about time scale this whole ordeal happened in September so a full 10-11 months after Emily broke up with my pal. 

Anyway we're in the process of buying our first house together and we're so happy I love her to bits she's a wonderful caring person and I'm happy to have gone through all the shit for her but it still plays on mind whether I did my buddy wrong so Reddit AITA?

TL;DR - Went travelling with my buddy's ex girlfriend 10 months after they broke up and hooked up with her we've now been together over 18 months. 