Thank you for your question and sorry you had to wait so long for an answer!
I am not familiar with the specific Italian context, but in general, authorities might indeed investigate on your case / challenge your refugee status if you marry someone of the opposite sex after receiving asylum due to your LGBT rights. However, if you mentioned you were bisexual (not homosexual) in your asylum claim you can argue that marrying someone of the opposite sex does not change anything to your situation.
I highly recommend you to contact a lawyer specializing in migration law / LGBT rights before your marry, in order to get personalized advice and be ready to react if anything happens.
I hope this helps. Don't hesitate to add a comment if you need additional information!
All the best,