State of UP Vs Babul Nath (1994) 6 SCC 29 Supreme Court

Hon’ble Supreme Court of India observed as under

"To constitute the offence of rape neither Section 375 of IPC nor the Explanation attached thereto require that there should necessarily be complete penetration of the penis into the private part of the victim/prosecutrix. In other words to constitute the offence of rape it is not at all necessary that there should be complete penetration of the male organ with emission of semen and rupture of hymen. Even partial or slightest penetration of the male organ within the labia majora or the vulva or pudenda with or without any emission of semen or even an attempt at penetration into the private part of the victim would be quite enough for the purpose of Sections 375 and 376 of IPC. That being so it is quite possible to commit legally the offence of rape even without causing any injury to the genitals or leaving any seminal stains. But in the present case before us as noticed above there is more than enough evidence positively showing that there was sexual activity on the victim and she was subjected to sexual assault without which she would not have sustained injuries of the nature found on her private part by the doctor who examined her."

Uday Vs State of Karnataka 2003 CriLJ 1539

IPC -376- rape- consent - for determining whether consent given by the prosecutor was voluntary or under a misconception of fact, no straitjacket formula can be laid down but following factors stand out;
(i) where a girl was of 19 years of age and had sufficient intelligence to understand the significance and moral quality of the act she was consenting to;
(ii) she was conscious of the fact that her marriage was difficult on account of caste considerations;
(iii) it was difficult to impute to the appellant knowledge the prosecutor had consented in consequence of a misconception of fact arising from his promise, and
(iv) there was no evidence to prove conclusively that the appellant never intended to marry the prosecutor.