I'm not sure whether it just look like it, because of the video quality, but I have the impression that your friend, when jabbing, pulls his guarding right hand back and leaves his face open to counter jabs of your own. You may want to check on that with him.
Anyways, suggestions for feints (to add some punch-kick/kick-kick feints to the punch-punch feint in your video):
- One that is pretty easy, but works very well is a front kick - question mark kick combo: 2-3 front kicks to the belly to make your opponent lower his/her guard and then starting a front kick, but in mid-kick motion going high to the head with a round house. This question mark kick has not the same power as a regular round house kick, but it's way harder to predict where it lands.
- hook-spinning back kick combo: 1-2 jab - hard left hooks to your opponent's head making him pulling up his guard, then visibly loading up for what looks like another real hard left hook, so your opponent pulls up his guard again (opening his body) and makes a step back (placing himself for you into kicking distance), but you deliberately miss with your hook right in front of his face to obstruct his vision and turn further into a spinning back kick to the liver.
- low kick - rear lag attack: 1-2 jab-cross-low kick combos, making your opponent anticipate more low kicks to come and pulling his leg up to check the next low kick, but after the next jab-cross combo your "low kick" goes lower under his lifted lag and is actually aimed at his standing rear lag. That attack doesn't have the same power as a regular low kick, but can work like a sweep and put your opponent off balance so that you can follow up.