Piranha II: The Spawning (1982) review

Genetically-altered piranha from the Vietnam years - that are larger-sized and have wings - are gobbling up tourists at a Caribbean resort, so it's up to police officer Steve (Lance Henriksen) and his "wife," SCUBA instructor Anne (Tricia O'Neil), to try and stop them ... and that involves using dynamite to blow up the ocean.  Cameron's "supposed" directorial debut (it's up for debate how much of it was actually recorded by him) is quite the doozy, and I knew it was terrible when I initially saw it as a kid ... but it's also unintentionally hilarious in parts, from the opening scene with two divers having sex underwater to Anne breaking into a morgue with a bank card to the ravenous fish literally flying onto the beach to chew on faces.  The first movie at least understood its function as a spoof while this stupidly tries being "serious."  But here's a little detail I didn't think about as a youngster (and reasonably so): what's going on with Steve and Anne's "marriage?"  Is it an open arrangement?  Does she have a free pass?  Is Steve a secretly happy cuckold?