1) Both infinitive "to watch" and gerund "watching" can be joined to the verb "love" without meaning differences between combinations. Though the infinitive is frequently used in designation of an action in the future or some single action, and the gerund - to show the action that is taking place at the moment or any continual activity in general. For example:
I prefer to wait here ("I shall wait here. This time").
I prefer waiting here ("I've been already waiting here for some time" and/or "I wait here every time").
2) Moreover, in British English the verb "like" is used with the gerund in the meaning "love", "enjoy". And when "like" is used with the infinitive it means "prefer", "consider smth. to be efficient, reasonable", but it's not sure to be pleasing. Compare:
I like taking a shower in the morning ("I gladly take a shower every morning. There's nothing better").
I like to take a shower in the morning ("When I take a shower I probably find it enjoyable but that's not the point. I just think it quite proper to do in the morning").
3) The choice between infinitive and gerund depends on linguistic purposes of the statement. What does the author want to accent - a process, state or performance of an action? This also defines all nuances of translation into another language (such as pragmatic aspects and so on).
Anyway there's no need to plunge into the depth of such a disputable question. Both variants are replaceable in English.
And yes, thanks for reading this stuff to the end.