It never really bothered me, to be honest. Just two harmless pecks on the lips, no tongue. Easy enough to imagine one friend doing to another who she may have had history with, especially after having had a bit to drink. Della comes across as the former sorority girl type, anyway.
In addition, the happy-go-lucky Felix at the end of the film was also a bit creepy, as well. Did he quickly forget his VERY recent maiming and death of his wife while he was making those fishing plans with James? (Ah, it must have been the drugs they were giving him!)
The above, however, does bother me. The only saving grace is the somewhat downbeat way they say goodbye to each other, offering the possibility that we only caught the end of a conversation, with Leiter trying in vain to pretend like these were old times, at least for a second - but while Dalton's acting allows that interpretation IMO, Hedison's blatantly precludes it.
I also hate Bond jumping into the pool for Pam at the end. Can somebody explain that scene to me?
I took it, much like the earlier scene where Bond briefly and oh-so-casually celebrates his recently acquired wealth after one epic, middle-finger-to-Krest-and-Sanchez of a battle, to be a moment where Bond is wringing whatever semblance of enjoyment and peace of mind he can out of an existence he knows to be fraught with loss and peril at every turn. He knows happiness is out of the question and contentment is fleeting, so he'll seize it when he can (and there's no business to be done at the time) - which explains, besides the obvious, why he slept with Lupe.
To be sure, Dalton's superb acting (and attempt to emulate the literary Bond) more than anything is what makes this interpretation so plausible and natural in my view. But it does jive with my impression of Dalton as the most utilitarian, the most "ruthlessly efficient" of all the Bonds.
Anyway, Pam crying was more of a problem for me than Bond jumping into the pool after her.