At the party, Bob felt

[Bassim]

I am wondering if my sentence sounds natural.

At the party, Bob felt that others would be pleased to see the back of him, so he excused himself by saying he was unwell and left.

 

[teechar]

I would use "the others" in that sentence.
In fact, I would phrase it as:
Bob felt that the (other) people at the party would be pleased to see the back of him, so he excused himself by saying he was unwell and left.

If we're not talking about everybody at the party, keep "other"; otherwise, you can remove it.