Why can't I tap to view my Connection's partner?

If you see someone you like but can't tap on their partner, it's because they have an old-style couple account

In the past, we allowed couples to share a unique Feeld profile. We have phased couple profiles out, and most couples now use Paired profiles, which means that each member operates a unique account, and that these accounts are linked. However, some couples still use old-style couple profiles.

You should be able to tap on your Connection's partner if they use a Paired profile. If they use an old-style couple account, this is not possible, but as both members use one account, these accounts often have photos and details of both members of a couple.