Even if your hunch is right on the money this time ... maybe ... probably ... people have been known to sniff shirts to see if they need laundering, not necessarily because they're ready to loose the love-hounds. You could give her the benefit of the doubt, since it's not as though she had her nose buried in his underwear.
He walks into his brother's room, sees her sniffing his brother's shirt, and automatically jumps into emotional attack mode. Even she hasn't untangled her feelings yet, so why is he assuming the worst and getting ready to fire off the big guns?
Even if your hunch is right on the money this time ... maybe ... probably ... people have been known to sniff shirts to see if they need laundering, not necessarily because they're ready to loose the love-hounds. You could give her the benefit of the doubt, since it's not as though she had her nose buried in his underwear.