pull someone's leg

verb2

1. •
   To tease someone; to lead someone on; to goad someone into overreacting.

   • I hadn't pulled Mrs. Barstow's leg for any of that stuff, she had just handed it to me on a platter, and that wasn't my fault. — 1934
2. •
   (no longer used) To extract money from someone (by taking out a loan or by swindling).

   • I'm very glad to hear of his good fortune; but it's a deuced strange thing, for I saw him at the club last night and he never said a word of it. I'll pull his leg when I see him. — 1886