I'm prepared to be told that IABU, but here goes. Apologies in advance for epic length - I am naturally longwinded. 
We live on a friendly street that has a mix of students and families with young children. One family popped an invite through our door that said, "Hello X Street neighbours, please come round to ours on Sunday afternoon for mulled wine and mince pies." We know lots of families on the street but not this one (although we do give them a friendly nod in passing) so I assumed they were trying to get to know their neighbours better and thought it might be nice to go round and meet them.
On the day of the event, we also received a Christmas card through the door from the house of students who live opposite us - we don't know them either, but they often say hello to our DC. The students' card said, "Hope to see you later today for a glass of mulled wine with Family Z". I was a little surprised to see another mention of the mulled wine event on the students' card, since I hadn't realised that the students and Family Z even knew each other, but again, I thought it was a nice gesture.
At any rate, DH and I turned up with the DC in tow. There was a house full of smiling, friendly people, but it quickly emerged that only Family Z and the students were actually from our street. It was actually a gathering of people from a local evangelical church, one that is very keen about proselytising. DH and I, and one other unsuspecting couple, were the only newcomers and non-church members present.
No one tried to push religion on us, the mulled wine was excellent, the DC had a blast playing with one of the other children, and the adult conversation was pleasant too although my DH did say on the way home that the women seemed a little Stepford-like. The wife took down my phone number and we discussed getting our toddlers together for a playdate.
However, when I got home I looked up the church website because I was curious to see what it was like. The father from Family Z is a new assistant pastor there and he and his wife seem to be at the forefront of lots of initiatives to "share the love of Christ with your community", etc. The church platform is quite conservative: women can't be ordained as pastors, homosexuality is a sin and so on.
So AIBU to feel a little conned? To say "My neighbours invited me round for mulled wine and they invited all their Christian friends too!" sounds like a ludicrous complaint. But I thought that the people from these two houses were making a friendly gesture because they liked the look of us - now I just feel that the friendliness had an ulterior motive. And it is partly just chance that I discovered this motive so fast. I am very chatty not to mention a busybody or otherwise I would not have realised that everyone else in the room was from the same evangelical church.
I will be polite to them now but there is no way I would seek them out to socialise with them again. The homophobia is a deal-breaker for me.
Shrugging, moving on, but still grumpy.
It takes all kinds to make up a street, I guess.