That's up to you; he's your character. I don't think that there would be much of a love triangle left. Lucas has moved on to other tails to chase, and Cassidy is more interested in pushing their sect of the program to the top, above all other supers programs. I'm sure Lucas might have loved rubbing it in Ian's face at the time, though, all in good fun, and he would of course encourage Ian to move on now. Ian would be exactly the sort of friend Lucas would want, one who could take many of his gestures in good humor as they're intended.