Yeah this is not going to end well for the childhood friend.
The girl spent the chapter fawning over how charming the older guy is and trying to avoid the question of if she likes him by saying how he probably doesn't view her as a possible lover (which is basically inadvertently admitting she likes the older guy). So the childhood friend decides that's the perfect moment to hold her down, confess his feelings, and kiss her full on the lips. A kiss that she's not seeming all that into, by the way.
I expect this to go either one of two ways;
1. The girl runs away and/or rejects his feelings for both the "sake of their friendship" and also she clearly has feelings for the older guy.
2. The girl "accepts" the childhood friend's feelings and goes out with him while in actuality, she'll still want to be with the older guy and the NTR commences.
I prefer if the author goes with the former option, because I detest NTR. Regardless, no matter what this kid does, the childhood friend NEVER WINS.