When it comes to sexual relationships, consent is key. In the eyes of the law, if you have given your free and informed consent, you have established a legal and valid consent to engage in a sexual relationship. This is in accordance with Section 90 of the Indian Penal Code (IPC).
It is important to note that under the definition of rape as stated in Section 375 of the IPC, consensual sex cannot be considered as rape. As such, if the sexual relationship was established with your free consent, your boyfriend has not committed any offence under this section. Therefore, you cannot file an FIR under Section 376 of the IPC.
However, if your boyfriend has uttered indecent words with the intention of insulting your modesty, he has committed an offence under Section 509 of the IPC. You have the right to file an FIR against him in this regard. It is important to know your rights and take appropriate legal action if necessary to ensure that justice is served.