Your opponent is attempting to pass your guard. They one arm wrapped around your top leg and they are controlling your bottom leg against the mat.
If you let them progress they will smash your legs and complete the pass.
Don't let your legs be lazy. Use them in an assertive manner to control your opponent and, as if you were hitting a scissor sweep, create enough movement to get your opponent off balance.
(Pay attention to the leg and feet positioning, and how you are creating pressure with your top leg against their hip)
When you do this, you will have enough space and time to free your bottom leg and place your foot on the hip, establishing a much better open guard position.
Now you can attack the arm they were using to hold your lapel. Switch your hip position and place your left foot on the hip as you go around with your right leg over their arm to finish in an armlock.
Pay attention to the small details on the different ways to finish this armlock.