The act or state of practicing infidelity.
(quality; condition; process); infideliousness
Unfaithfulness to a moral obligation to another.
A broken promise of monogomy to one's significant other.
Disloyalty to one's mate.
cheater liar two-timer
"Hey! Look! There goes (yet) some more grubby AIDS-riddled whores for him/her to be infidelious with!"
"Without her knowledge, behind his girlfriend's back, he often trolled the internet, preying on naive, lonely, and attention-starved girls to act out his infideliousness with. Yeah, he was a real piece of shit!"