I had 2 tanks when I was with my ex. One was a 50 gallon with an Angel, 2 pleckos and at least 4-5 other various pairs, a few snails and ghost shrimp. My second tank had my female betta and a snail. While we were together he took care of the maintenance, WC etc, and I took care of the fish because they were mine and my sons'. Sadly since we split he is "maintaining" the tank until the fish die. I'd take them but I live with my parents and we don't have the room.Mother thinks it is completely absurd I have 3 tanks.
However, once I moved home I missed my fish. My bf bought a 1 gallon tank so I could have another betta. The tank didn't have a filter or anything so he bought me a 3 gallon. He fully supports my hobby with my "baby". My parents and brother are supportive as well. My dad just requested I stop at the 3 gallon tank.
I'm sorry your SO is giving you a hard time. I thought my dad would but as long as the lights aren't in his eyes I think he finds the tank relaxing. Not that he'd ever admit it.
I also don't think they have "soulless glares" at all. In fact, sometimes I swear I can see Panda working something out in head. Heck, if I put my lips to the tank he swims over and touches his face to glass. That's as far as our relationship goes though. I don't love him *that* much.