1. Animals love Sirius. There's a hint of it in canon, with Crookshanks and Buckbeak, but it's actually all animals. Nifflers bring him presents. Adult unicorns let him pet them. Underhanded tricks have been played on unsuspecting Slytherins when Sirius charms their owls into doing him favours. As a child Sirius was never allowed pets because the Blacks didn't want dirty, common things in the house (even post owls had to live outside), but the Potters gave him a kneazle. Remus is not jealous about it getting to sleep in Sirius' bed, don't be silly.

2. Remus is a fashion disaster. It started as just "not much money, don't really care" so why not wander about in corduroy and terrible jumpers, in unbecoming shades of brown, mustard, and orange? Remus is initially baffled at how the whole Geography Teacher aesthetic makes Sirius hot for him, but it works out pretty well for him so he's not going to complain. And maybe he plays it up a bit because he knows what it does to Sirius but you can't prove anything.