How to watch avengers

To keep the couple together, we temporarily treat them as one person. Then we are arranging five "people", which can be done in $5!$ ways. Once that's done, the couple itself can switch seats among themselves, which can be done in $2!$ ways. So the number of ways the six can sit keeping the couple together is $5! \cdot 2! = \boxed{240}$

The couple must be placed together and we can ignore them for the moment. The remaining 4 friends can be placed in the other 4 seats in 24 ways - there are 4 different people who can go in the first seat, 3 in the second, 2 in the third and 1 in the fourth, multiply 4 by 3 by 2 by 1 and you get 24. The couple can be placed in 5 ways: seat 1 and 2, seat 2 and 3, seat 4 and 5, seat 5 and 6. However, the two people in the couple can be swapped around doubling the numbers of possible combinations for the couple to 10. 24 multiplied by 10 is 240.