is it cheating?

If you feel guilty and have to hide it from your significant other, then yeah it's cheating

Yes i think it's cheating but i think you need to be clear with you gf because it''s what really matters.

of course is cheating
they're having a sexual/romantic conversation, aren't they?

It's cheating the moment you show your feelings (sexually / love wise) to anyone but your girlfriend / boyfriend

I really don't know what to expect from the human race when some people can be as dumb as this

My opinion is: your gf mustn't even talk with other boys, this is about physiology - when girl talk with boy they produce hormones and something going on and then they could f*ck, like that

yeah, if she knows about it that wouldn't be cheating ,otherwise it's cheating.

depends what type of relationship you have i guess, im sure most people would see it as cheating though

I'd say it is cheating as you are thinking about another person sexually and sending pictures to each other without your other half knowing, which is cheating. But it all comes down to what you and your partner have agreed on what constitutes as cheating as every relationship is different.

Just listen what you feel inside, when your GF will send nudes. Thats will be an answer)