You think it was dumber than "we both had sex with the same dead guy. Doesn't make us friends.?? The whole first half of it was cringey, then the saviors saved it. It's hilarious what shutty shape everyone is in due to Negan. He's this huge force of nature beep up everyone but he's such a goof.

I have a feeling they're setting up for him to rat Rick out to Negan to save him and his boyfriend
"The saddest thing in life is wasted talent." ~ A Bronx Tale (1993)

The episode had a lot of dumb lines. Jesus waiting for the Kingdom horsemen was the dumbest to me. But the line you mentioned was pretty cliche too. It made me think, if anyone claims to love me, but doesn't love their fellow human beings just as much, then they're really not a good relationship partner for me. With or without a zombie apocalypse, there's no room for small-hearted love.

Soo - "I care about us (our relationship) being alive, the both of us (referring to them as people)" just sounds convoluted and a bit dumb.
Still, the fact you have to explain it shows that it was a poorly written line. Just sounds redundant and stupid tbh, even with an explanation.

Tried to dumb it down for you

Us, as in their relationship, and both of us, as in each individually