Is feeling remorse and seeking forgiveness sufficient after saying "A'udhu billahi minash-shaitanir-rajeem" (I seek refuge in Allah from the accursed Satan) upon seeing a girl and attempting to do things that would please her?

Whoever intentionally utters forbidden speech, such as backbiting (gheeba) and slander (nameema), must offer sincere repentance by refraining [from it], regretting it, and resolving not to return to it. One should recall the sanctity of refraining from such acts and the punishment for those who commit them, associate with righteous women, and accustom the tongue to the remembrance of Allah, the recitation of the Qur’an, and good speech. As for seeking refuge with Allah (isti‘adha) upon seeing a girl, if it is done secretly and no one hears it, there is no blame. However, caution is necessary, and adherence to the methods mentioned is important.