Are there any incidents of a love interest cheating on the main/titular hero?

[Frontier]

Sure, but the unwritten Bro Code stipulates you don't go ploughing a field your mate has already worked.

Still not cheating (and Conner was technically dead, so...).

[Tzigone]

Sure, but the unwritten Bro Code stipulates you don't go ploughing a field your mate has already worked.

Which still would not be the partner cheating. Also, it's very gross to speak of women as inanimate things that way. Objectively objectifying, even.

[NaVi]

Sure, but the unwritten Bro Code stipulates you don't go ploughing a field your mate has already worked.

Exactly, Cassie not only goes with another, if not with a friend, that's what women of the worst class do, of course the friend is just as bad. Conner deserves someone better.

[John Venus]

^ They both bonded over tragedy which blossomed into a romance. Again, Connor was dead. Tim and Cassie both consented to the relationship. There is nothing wrong with that.

[Superfan90]

The person might be referring to the time she kissed Lex in the Death of Superman animated movie. But that was only to trick him so she can get access to his Superman cloning lab. That was all well after Superman died and there was a clone Superman running around.

He is talking about Jeb Friedman, a side character in the comics who Lois kissed after Superman was resurrected but it was out of grief and she regretted it immediately.

[M L A]

shoutout to that time Jade got horrifically character assassinated to make readers feel bad for Kyle

[married guy]

Yeah, that one didn't sit well with me.

[marshal88]

old dicky boy had dreams of raven while with kory.

[John Venus]

Dreaming of doing it with a girl while your other girl is repeatedly yelling 'Dick' then getting engaged with the latter girl but then go sleep with your old teenage crush a few days before the wedding, all the while telling your fiance that their relationship is conditional on not being an open one. Oh and he also got raped by Mirage during that time. Man, Dick Grayson's a mess.

[Agent Z]

^ They both bonded over tragedy which blossomed into a romance. Again, Connor was dead. Tim and Cassie both consented to the relationship. There is nothing wrong with that.

And Conner wasn't even mad about it from what I remember.

Dreaming of doing it with a girl while your other girl is repeatedly yelling 'Dick' then getting engaged with the latter girl but then go sleep with your old teenage crush a few days before the wedding, all the while telling your fiance that their relationship is conditional on not being an open one. Oh and he also got raped by Mirage during that time. Man, Dick Grayson's a mess.

Also, Raven's out of control powers were making him have those dreams.

More often than not, Dick's the one getting the short end of the stick from his love interests.

[marshal88]

dick was hardly innocent

[Will Evans]

dick was hardly innocent

Hasn’t Barbara ever hard of “one last fling before tying the knot?”

[DrNewGod]

dick was hardly innocent

Yeah, DC made a mess out of poor Grayson for a while. I never blame characters, just the creative teams.

[Frontier]

dick was hardly innocent

...Not Dick's best moment.