20. In this Part—

“sexual act” means—

(a) an act consisting of—

(i) sexual intercourse, or

(ii) buggery,

(b) an act described in section 3(1) or 4(1) of the Act of 1990, or

(c) an act which if done without consent would constitute a sexual assault;

“sexual intercourse” shall be construed in accordance with section 1(2) of the Act of 1981.