<human>: Aloha. (I'm not actually from Hawaii.)

So, I have a pretty big crush, and I'm kinda uncertain on how to proceed. For the last couple weeks, I've been thinking of asking Arthur (not my friend's real name) for advice on the matter. I've known Arthur for over a year and a half, and I sincerely trust him.

The trick here, though, is not hurting his feelings. Last year, Arthur was in a relationship with a girl for a quite a while (and it was a pretty intimate relationship at that). A few months ago, however, Arthur's girlfriend came out to him as a lesbian, and she is currently in a relationship with another woman.

I'm sure I could benefit from Arthur's advice (if he has any to give), but I don't want to put salt in an already painful wound. Arthur and his ex are friendly enough at school, but he has said on several occasions that their relationship as a whole is still relatively caustic. How do I ask for his advice on romantic issues without providing him with a metaphorical slap in the face?

Summarize the given text in a few sentences.
<bot>: I want to ask a friend for romantic advice, but don't know how to without reminding him of a past relationship. How should I ask him?