I think it was important for him not to overly 'sexualize' their relationship. I think he wanted the focus to be on their emotional bond rather than guys getting all stupid over the "hot lesbian chicks" and missing the importance of what was really going on.
I think the hand-holding is intimate enough- especially when accompanied by the other, more sexual scene between them.
"than guys getting all stupid over the "hot lesbian chicks" and missing the importance of what was really going on."
Which of course, if anyone is thinking like that is really dumb since only one of them is a lesbian, and that's of course Taryn. But Kristen on the other hand is obviously bisexual.