I agree it is deception and I would want this to be law that one couldn't lie about birth control to get sex.

The problem is that does it rise to the level of criminality?

Well that's kind of why I opened this conversation up to see what people think, I think yes as I only gave consent based on false pretence, and not in a vague way at all.

Cheating is deception. Should we jail people for that? Do we jail them for lying to their partner or for lying to the person they cheat with (if they withheld the fact they are in a relationship?)

Very interesting question. I don't think the relationship itself should be illegal but being decieved into sex could be eg. If she was to explicitly state she was not sleeping with anyone else to her husband get into having sex w him then that is decieving. If someone meets someone and has sex with them and that person is already having sex with someone else, I don't believe that is criminal no, but if one goes out of their way to say they don't want sex if they've got a sexual relationship already w someone else and they lie about it to get the consent then that's not really consent.