if I must I suppose

[ostap77]

A. "Who wants a tequila shot?"
B. "Oh God! If I must I suppose."

What would speaker B be trying to say?

[5jj]

Speaker B is pretending to be reluctant to have the drink.

[Bennevis]

A. "Who wants a tequila shot?"
B. "Oh God! If I must, I suppose." I guess if I must (if you insist or if it's part of the event) have a tequila shot, I will have one.

If you want me to have a tequila shot, I will have one.
If you insist that I have a tequila shot, I will have one.