Bi:
Rachel Summers, Cypher, Storm, Yukio, Pixie, Wolverine (Logan), Wolverine (Laura)
Ace:
Magik
Gay:
Sunfire
Les:
Callisto
Most women Claremont wrote read as bi.
Callisto did have the whole thing where she had Angel in non-consensual bondage and planned to "marry him". She reads as very bi/pan to me.
Yukio and Storm are lovers, the intent is clear.
I think Cypher and Warlock have been married forever, but Cypher is too clueless to be aware. All that body merging, and the AIDS subtext of the techno virus in the 80s, is pretty compelling.