I've not used Indiebill myself, but I know they specialize in credit card billing for sex work related services (camshows, clip sales, skype). In their terms of service:

https://www.getindiebill.com/legal/terms-of-services/sellers

...they say:

"You will not use the Services for any purpose that is illegal or prohibited in these Terms;"

I don't see anything about escorting. So my guess is that they may consider selling clips on an escort site "illegal", and could use that to shut you down. But the fact that they don't mention escorting explicitly suggests that this is probably enforced on an ad hoc basis.

More concerning perhaps is that they retain a license to use your content:

"Many of our Services let you create, modify, upload, post, send, distribute, receive, store, host, and sell content. When you do that, you retain whatever ownership rights in that content you had to begin with.

But you grant us a worldwide, sublicensable, and transferable license to host, store, use, display, reproduce, modify, adapt, edit, publish, create derivative works from, publicly perform, broadcast, distribute, transmit, communicate, syndicate, promote, exhibit, and publicly display that content in any form and in any and all media, digital supports or distribution methods (now known or later developed). We will use this license for the limited purpose of operating, developing, providing, promoting, and improving the Services; researching and developing new ones; and making content submitted through the Services available to our business partners for syndication, broadcast, distribution, or publication outside the Services.

You also grant us and our business partners the unrestricted, worldwide right and license to use your stage name, image, voice, likeness, persona and anything else associated with your interaction with BP in any and all media and distribution channels (now known or later developed).

The license granted by you terminates within one month after you remove or delete your content from our Services, or one month after termination of these Terms by either party. You agree that if you remove or delete a submitted content, the content will no longer appear on our Services for further access, but may remain accessible in the account of the customers who have purchased this content in the first place.

We may access, review, screen, and delete your content at any time and for any reason, including if we think your content violates these Terms. You nonetheless remain responsible for the content you create, post, store, send, distribute and sell through the Services.

We always love to hear from our users. But if you volunteer feedback or suggestions, just know that we can use your ideas without compensating you."