"Glue-gunning" means "to use a glue gun.
"Love" "glue-gunning" means to use a figurative glue gun to stick two people together,
or at least specific parts of their anatomy.
While more commonly practiced than most hetrosexuals would imagine by the general homosexual public, the act of gluegunning can also be seen in many gay pornographic workings.
Person 2: It's called gluegunning, son!